vlan usage requires an intermediate step

[Mathieu Trudel-Lapierre]

If I try to apply vlans directly:

network:
  version: 2
  renderer: networkd
  ethernets:
    eth0: {}
  vlans:
    vlan1:
      id: 1
      link: eth0
      addresses: [ 192.168.0.10/23 ]
    vlan10:
      id: 10
      link: eth0
      addresses: [ 10.0.0.5/24 ]

The vlan devices never come up, they are left in degraded state by networkd. If I define an address for eth0, then eth0 and all of the vlans will have the same address. Needless to say, this doesn't work.

If I use an intermediary device instead, such as a bond:

network:
  version: 2
  renderer: networkd
  ethernets:
    eth0: {}
  bonds:
    vmaster:
      interfaces: [ eth0 ]
  vlans:
    vlan1:
      id: 1
      link: vmaster
      addresses: [ 192.168.0.10/23 ]
    vlan10:
      id: 10
      link: vmaster
      addresses: [ 10.0.0.5/24 ]

Then the vlans are correctly applied and brought up by systemd.

I think this is either a systemd bug or a netplan bug; it's possible we don't generate the config quite in the way that systemd expects it (even though it looks straightforward enough).

[Dimitri John Ledkov (xnox)]

That sounds like a bug.

I have only previously used vlans on top of bonds.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Dan Streetman (ddstreet)]

please reopen if this is still an issue

[Lukas Märdian (slyon)]

This seems to be working nowadays. I cannot reproduce using the config provided in the description:

$ netplan apply
$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: vlan10@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:f5:92:b3 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.5/24 brd 10.0.0.255 scope global vlan10
       valid_lft forever preferred_lft forever
    inet6 fe80::216:3eff:fef5:92b3/64 scope link tentative
       valid_lft forever preferred_lft forever
3: vlan1@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:f5:92:b3 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.10/23 brd 192.168.1.255 scope global vlan1
       valid_lft forever preferred_lft forever
    inet6 fe80::216:3eff:fef5:92b3/64 scope link tentative
       valid_lft forever preferred_lft forever
84: eth0@if85: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:f5:92:b3 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::216:3eff:fef5:92b3/64 scope link
       valid_lft forever preferred_lft forever
$ networkctl
IDX LINK TYPE OPERATIONAL SETUP
  1 lo loopback carrier unmanaged
  2 vlan10 vlan routable configured
  3 vlan1 vlan routable configured
 84 eth0 ether routable configured

4 links listed.

Please re-open if this is still an issue.